Portable illumination devices, such as flashlights and head lamps that can be worn, for example, on the helmet of a miner or cave explorer, typically emit light in a forward direction or in a forward direction and to the sides. Some devices include adjustable features to allow the user to pivot, focus, and/or direct the illumination, allowing the user to adapt a limited (focused or directed) emitted-light pattern to best suit the user's situation. Unfortunately, such limited emitted-light pattern produces “tunnel vision” effects, in which only a very narrow central region of vision remains due to the limited illumination.